Gamma,infra-red and microwave radiation combinations for control of Rhyzopertha dominica in wheat

Samples of soft winter wheat containing eggs, larvae, pupae, or adults of Rhyzopertha dominica (F.) were given one of the following treatments: (1) Gamma radiation; (2) infra-red radiation; (3) microwave radiation; (4) gamma + infra-red; or (5) gamma + microwave. The percentage of adult emergence from treated immatures or the mortality and fecundity of treated adults provided a basis for evaluating the effectiveness of the treatments.The average reductions in emergence were 54, 55, and 42 per cent for gamma, infra-red, and microwave treatments, respectively. The reductions in emergence averaged 99 per cent for the gamma + infra-red combination and 96 per cent for the gamma + microwave combination. These mortalities were about 20 per cent higher than predicted. Adult mortality data were inconclusive because of the very low gamma dosage used. However, reductions in adult fecundity for the above combinations were about 95 and 89 per cent, respectively. These were about 22 and 9 per cent greater than the predicted reductions in fecundity.     

SYNTHESIS OF ACTIVATED CARBON FROM JATROPHA SEED COAT AND APPLICATION TO ADSORPTION OF IODINE AND METHYLENE BLUE

This article provides evidence that jatropha seed coat residues can be used as a carbon source for preparing activated carbons that have good adsorption properties for iodine and methylene blue. Activated carbons were prepared using three different methods of activation, physical, chemical, and physico-chemical, for a range of activation temperatures (600°, 700°, 800°, and 900°C) and activation hold times (1, 2, and 3 h). The highest BET surface area (1479 m² g^?1) and the highest iodine adsorption (1511 mg g^?1) were obtained with physico-chemical activation at a temperature of 900°C and a hold time of 2 h. This activated carbon gave higher BET surface area and iodine adsorption than commercial activated carbon (1169.1 m² g^?1 and 1076 mg g^?1). The activated carbons prepared by physico-chemical activation at 900°C and 2 h were then tested for adsorption of methylene blue at a range of concentrations of methylene blue (100, 200, 300, 400, and 500 mg L^?1). It was found that a Langmuir isotherm gave a better fit (R ² = 0.999) to the observed adsorptions than a Freundlich isotherm (R ² = 0.884). For the adsorption kinetics, a pseudo-second-order model gave a better fit (R ² > 0.998, Δq _e  = 3.7%) than a pseudo-first-order model (R ² ≈ 0.95, Δq _e  = 85.6%). These results suggest that chemisorption is the rate-controlling step for the adsorption of methylene blue. The experimental results show that jatropha seed coat is a lignocellulosic waste precursor for preparation of activated carbon that is an alternative source for preparation of commercial-grade activated carbons.